package com.heima.sample;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerQuickStart {

    public static void main(String[] args) {

        //1.kafka的配置信息
        Properties prop = new Properties();
        //链接地址
        prop.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.162.132:9092");
        //key和value的反序列化器
        prop.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        prop.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");

        //设置消费者组，同一个消费者组只能有一个接收到消息
        prop.put(ConsumerConfig.GROUP_ID_CONFIG, "group2");

        //手动提交偏移量
        //prop.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);


        //2.创建消费者对象
        KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(prop);

        //3.订阅主题，subscribe参数为集合，所以将"topic-first"转为集合
        consumer.subscribe(Collections.singletonList("topic-first"));

        //4.拉取消息

        //同步提交和异步提交偏移量
//        try {
//            while (true) {
//                ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
//                for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
//                    System.out.println(consumerRecord.key());
//                    System.out.println(consumerRecord.value());
//                    System.out.println(consumerRecord.offset());
//                    System.out.println(consumerRecord.partition());
//                }
//                //异步提交偏移量
//                consumer.commitAsync();
//            }
//        } catch (Exception e) {
//            e.printStackTrace();
//            System.out.println("记录错误的信息：" + e);
//        } finally {
//            //同步
//            consumer.commitSync();
//        }


        //使得该方法可以一直执行，一直监听
        while (true) {
            //消息拉取频率，毫秒
            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
                //System.out.println(consumerRecord.offset());
                //System.out.println(consumerRecord.partition());

//               *//* try {
//                    //同步提交偏移量
//                    consumer.commitSync();
//                }catch (CommitFailedException e){
//                    System.out.println("记录提交失败的异常："+e);
//                }*//*
            }
//            //异步的方式提交偏移量
//            *//*consumer.commitAsync(new OffsetCommitCallback() {
//                @Override
//                public void onComplete(Map<TopicPartition, OffsetAndMetadata> map, Exception e) {
//                    if(e != null){
//                        System.out.println("记录错误的提交偏移量："+map+",异常信息为："+e);
//                    }
//                }
//            });*//*


        }

    }

}
